Escalators or moving walkways are known as representative examples of passenger conveyors, which can transport humans or articles over a relatively short distance. The escalator is a system in which step-shaped treads and handrails, which are grasped by the hands of the passengers, are automatically put in motion. In the moving walkway, plate-like treads, which are commonly referred to as “pallets,” and handrails are automatically driven.
The treads on which humans or articles are carried are continuously put in motion when in operation. The handrail also makes a continuous movement over an edge of a balustrade, which flanks the tread. The endless movements of the treads and handrail should be identical in terms of their moving speed for the safety of the passenger.
An important factor that should be considered in designing these systems is to reduce the noise and vibration when in operation for enhancing the ride of the passenger. This is because the systems include a number of components, which is characterized by, for example, rolling contact movements, rotational movements or sliding contact movements.
In FIG. 1, there is shown a prior art escalator 12. As shown therein, handrail 16 is adapted to accommodate the hands of the passengers. Handrail 16 is retained on an outermost section of a guide 28, which is attached to an edge of balustrade 18, and is moved at the same speed as the steps 14. When handrail 16 moves over the guide 28, frictional resistance is normally exerted to the handrail 16. The resistance is not great in terms of magnitude in the substantial straight section of the handrail 16. However, the resistance is remarkably increased in the curved section of the handrail 16, such as newels 26 of the escalator 12, due to a tension of the handrail 16.
As shown in FIG. 2, one attempt to reduce such frictional resistance is to provide a plurality of rollers 32 to newel 26. However, due to the tension of handrail 16, which is provided to prevent a deviation of handrail 16, the rollers 32 of newel 26 continuously receive a load in one direction.
As shown in FIG. 3, the load exerting in one direction easily damages the journal 54, which supports the shaft 58 of the roller 32, thus resulting in serious noises. Further, after a long-term service, dusts, chips (caused by wearing of the fabrics of an internal surface of the handrail), materials (e.g., particles of rubber or urethane from a driving unit of a handrail), etc., may be accumulated and then become solidified in vacant areas between rollers 32. Furthermore, such materials may enter between the shaft 58 and journal 54 so as to cause rotational problems of rollers 32, serious noises or vibrations.